Fig. 1. Diagram of flexible angular displacement adjustment device(a) Stereogram, (b) Main view and composition

Fig. 2. Principle of motion

Fig. 3. Diagram of parameters and deformation of right-circular flexible hinges

Fig. 4. Relationship diagrams between mechanism stiffness K and structural parameters:(a) t_a, t_b, (b) R_a, R_b, (c) r_a, r_b

Fig. 5. Relationship diagrams between natural frequency f₀ and structural parameters: (a) t_a , t_b, (b) R_a, R_b, (c) r_a, r_b

Fig. 6. Pareto front and optimal solution

Fig. 7. Modal analysis diagram of flexible rotary mechanism(a) First order modal, (b) Second order modal, (c) Third order modal, (d) Fourth order modal

Fig. 8. Testing system for flexible angular displacement adjustment device

Fig. 9. Bidirectional repeatability of movement at 7 μm

Fig. 10. Resolution measurement by 15 nrad step motion

Fig. 11. Stability of the mechanism in 30 min (from 1 Hz to 500 Hz)

Fig. 12. Spectrum diagram of the flexible rotary mechanism (color online)